Washing machine

ABSTRACT

A washing machine including a tub to retain wash water, a spin basket rotatably installed in the tub, a pulsator rotatably installed in the spin basket, a drive unit to generate rotary power and transmit the rotary power to the pulsator, and a float clutch elevatably installed at the pulsator to selectively transmit the rotary power to the spin basket when elevated by buoyancy. The float clutch includes guide protrusions provided at an upper surface thereof to allow the float clutch to be elevatably installed at a lower portion of the pulsator, and the pulsator includes guide grooved provided at a lower surface thereof, the guide protrusions being elevatably installed in the guide grooves. Since the float clutch receives rotary power at a position spaced apart from the shaft installation portion of the pulsator, the rotary power is prevented from being concentrated on the shaft installation portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No. 2012-0040314, filed on Apr. 18, 2012 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.

BACKGROUND

1. Field

Embodiments of the present disclosure relate to a washing machine having a float clutch to move and operate according to the level of water in a tub.

2. Description of the Related Art

A washing machine, which washes clothes using electricity, generally includes a tub to retain wash water, a spin basket rotatably installed in the tub, a pulsator rotatably installed at the bottom of the spin basket, and a drive unit to rotate the spin basket and pulsator.

In washing laundry, the rotary power of the drive unit is selectively transmitted to the pulsator, and thus the pulsator is rotated to generate water current in the spin basket, and thereby laundry in the spin basket is washed. In spin-drying, the rotary power of the drive unit is transmitted both to the pulsator and the spin basket, and therefore water is removed from the clothing as the pulsator and the spin basket rotate together.

Since the rotary power of the drive unit needs to be transmitted only to the pulsator in washing the laundry and to be transmitted both to the pulsator and the spin basket in spin-drying, the washing machine is provided with a clutch to allow the rotary power generated by the drive unit to be selectively transmitted to the spin basket depending on washing operation and water removing operation.

SUMMARY

Therefore, it is an aspect of the present disclosure to provide a washing machine having a simple structure and a float clutch which stably receives rotary power and transmits the received rotary power to the spin basket.

Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned from practice of the disclosure.

In accordance with one aspect of the present disclosure, a washing machine includes a housing forming an external appearance of the washing machine, a tub disposed inside the housing to retain wash water, a spin basket rotatably installed in the tub, a pulsator rotatably installed in the spin basket, a drive unit to generate rotary power and transmit the rotary power to the pulsator, and a float clutch elevatably installed at the pulsator to selectively transmit the rotary power to the spin basket when elevated by buoyancy, wherein the float clutch includes at least one guide protrusion provided at an upper surface thereof to allow the float clutch to be elevatably installed at a lower portion of the pulsator, and the pulsator includes at least one guide groove provided at a lower surface thereof, the guide protrusion being elevatably installed in the guide groove.

The at least one guide protrusion may include a plurality of guide protrusions extending in radial direction of the float clutch and arranged spaced apart from each other in a circumferential direction of the float clutch, and the at least one guide groove may include a plurality of guide grooves extending from the pulsator outward in a radial direction of the pulsator and arranged spaced apart from each other in a circumferential direction of the pulsator.

The pulsator may be provided, on an upper surface thereof, with a plurality of blades extending outward in a radial direction and arranged spaced apart from each other in a circumferential direction, the guide grooves may be formed at a lower side of the blades in a shape corresponding to a shape of the blades, and the guide protrusions may be formed in a shape corresponding to the shape of the guide grooves.

The drive unit may include a transmission shaft having an upper end coupled to the pulsator to transmit the rotary power to the pulsator, the pulsator may include a shaft installation portion extending from a center of a lower surface of the pulsator downward, the transmission shaft being installed at the shaft installation portion, and the float clutch may include a guide hole provided at a center thereof to allow the float clutch to be elevatably installed at the shaft installation portion.

The shaft installation portion may include a first uneven part provided on an outer circumferential surface thereof and provided with concave portions and convex portions alternately arranged in a circumferential direction of the shaft installation portion, and the guide hole may include a second uneven part provided on an inner circumferential surface thereof and provided with concave portions and convex portions alternately arranged in a circumferential direction of the guide hole such that the concave portions and convex portions of the second uneven part respectively match the convex portions and concave portions of the first uneven part.

The spin basket may include at least one coupling protrusion adapted to be selectively coupled to the float clutch depending on a position of the float clutch, and the float clutch may include at least one coupling groove formed on a lower surface thereof at a position corresponding to a position of the coupling protrusion and adapted to be selectively coupled to the coupling protrusion depending on the position of the float clutch.

The at least one coupling protrusion may include a plurality of coupling protrusions arranged spaced apart from each other in a circumferential direction, and the at least one coupling groove may include a plurality of coupling grooves arranged spaced apart from each other in a circumferential direction.

The spin basket may include a drive flange fixed to a lower end thereof to receive rotary power from the float clutch, wherein the drive flange may include a hub provided with a through hole allowing the transmission shaft to be installed therethrough, and a plurality of flange portions extending from the hub outward in a radial direction and arranged spaced apart from each other in a circumferential direction, wherein the coupling protrusions may be arranged at the hub in a circumferential direction.

In accordance with another aspect of the present disclosure, a washing machine includes a housing forming an external appearance of the washing machine, a tub disposed inside the housing to retain wash water, a spin basket rotatably installed in the tub, a pulsator rotatably installed in the spin basket, a drive unit to generate rotary power and transmit the rotary power to the pulsator, and a float clutch elevatably installed at the pulsator to selectively transmit the rotary power to the spin basket when elevated by buoyancy, wherein the spin basket includes a drive flange installed at a lower end thereof to receive power from the float clutch, the drive flange includes at least one coupling protrusion integrally protruding upward from the drive flange to be coupled to the float clutch when the float clutch is lowered, the float clutch includes at least one coupling groove provided on a lower surface thereof to be coupled to the coupling protrusion.

As described above, the washing machine according to one aspect of the present disclosure allows the float clutch to receive rotary power not only though the shaft installation portion but also through the guide groove, and therefore concentration of the rotary power on the shaft installation portion may be prevented, and thereby stable transmission of the rotary power to the float clutch may be ensured.

Also, as described above, the coupling protrusions are integrally formed at the drive flange, and therefore stable transmission of the rotary power from the float clutch may be ensured without using an additional component.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

FIG. 1 is a cross-sectional view illustrating a washing machine according to an exemplary embodiment of the present disclosure;

FIG. 2 is a perspective view illustrating installation of a float clutch applied to the washing machine according to the present disclosure;

FIG. 3 is an exploded perspective view illustrating a pulsator of the float clutch applied to the washing machine according to the present disclosure;

FIGS. 4 and 5 are cross-sectional views illustrating operation of the float clutch applied to the washing machine according to the present disclosure.

DETAILED DESCRIPTION

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.

As shown in FIG. 1, a washing machine according to the present disclosure includes a housing 10 forming an external appearance of the washing machine, a tub 20 disposed inside the housing 10 to retain wash water, a spin basket 30 rotatably installed in the tub 20, a pulsator 40 installed in the spin basket 30 to generate water current, and a drive unit 50 to rotate the pulsator 40.

The housing 10 includes a laundry inlet 10 a arranged on the upper surface thereof to allow a user to put laundry into the spin basket 30. At the rear end of the upper portion of the housing 10 is installed a door 11 hinged to open and close the laundry inlet 10 a.

The tub 20 is installed inside the housing 10 with a suspension to support the tub 20. A water supply unit 70 is disposed at the upper side of the tub 20, and a drainage unit 80 is disposed at the lower side of the tub 20 to discharge used wash water outside.

The water supply unit 70 includes a water supply pipe 71 connected to an external water source (not shown), and a water supply valve 72 disposed in the water supply pipe 71 to open and close the water supply pipe 71. The drainage unit 80 includes a drain pipe 81 connected to the lower portion of the tub 20 to guide water in the tub 20 to be discharged to the outside, and a drain valve 82 disposed in the drain pipe 81 to open and close the drain pipe 81.

The spin basket 30 includes, as shown in FIG. 2, a body portion 31 cylindrically shaped and having an open upper portion, and a bottom portion 32 fixed to the lower end of the body portion 31 to form the bottom surface of the spin basket 30. The body portion 31 is provided with a plurality of drain holes 31 a allowing water in the spin basket 30 to be discharged to the tub 20 during spin-drying. Also, a balancer 31 b is provided at the upper portion of the spin basket 30 to compensate for unbalance of the weight of the spin basket 30 such that the spin basket 30 stably rotates.

The spin basket 30 rotates, receiving power from the pulsator 40 via the float clutch 60, which will be described later. To this end, the spin basket 30 includes a drive flange 33 installed at the bottom portion 32 forming the lower end of the spin basket 30 to receive power from the pulsator 40. The drive flange 33 includes a hub 33 b provided with a though hole 33 a through which a transmission shaft 54, which will be described later, is installed, and a plurality of flange portions 33 c extending from the hub 33 b outward in a radial direction of the hub 33 b and fixed to the bottom portion 32 of the spin basket 30.

The pulsator 40 is adapted to rotate in a normal direction or reverse direction to generate water current in the spin basket 30, and the laundry in the spin basket 30 is churned by the generated water current and washed through friction. The pulsator 40 includes a shaft installation portion 41 protruding from the center of the pulsator 40 downward and having the upper end of the transmission shaft 54 of the drive unit 50, described below, mounted thereto to receive rotary power via the transmission shaft 54, and blades 42 provided at the upper surface of the pulsator 40 and extending from the center of the pulsator 40 outward in the radial direction of the pulsator 40 to generate water current according to rotation of the pulsator 40. The blades 42 are arranged spaced apart from each other in the circumferential direction of the pulsator 40.

As shown in FIG. 1, the drive unit 50 is disposed at the lower portion of the tub 20 and generates rotary power when electricity is applied thereto. The drive unit 50 includes a stator 51 having a coil 51 a, a rotator 52 including a magnet 52 a to interact with the coil 51 a and adapted to rotate through interaction with the stator 51, a rotating shaft 53 having a lower end connected to the center of the rotator 52, a transmission shaft 54 having an upper end connected to the center of the pulsator 40 to transmit rotary power to the pulsator 40, and a speed reduction unit 55 disposed between the rotating shaft 53 and the transmission shaft 54 and including a planetary gear to reduce speed.

Also, the washing machine includes a float clutch 60 allowing the rotary power generated by the drive unit 50 to be selectively transmitted to the spin basket 30 only when the laundry is spin-dried, so as to selectively rotate the spin basket 30 only in spin-drying operation.

The float clutch 60 is provided therein with an empty space filled with air, thereby achieving buoyancy through the empty space. Therefore, when the water level in the tub 20 rises above a certain level due to water filling the tub 20 as in the case of washing the laundry, the float clutch 60 moves up and remains elevated due to buoyancy. When the water level in the tub 20 falls below a certain level due to discharge of water in the tub 20 as in the case of spin-drying, the float clutch 60 moves down and remains lowered due to gravity.

In the illustrated embodiment, the float clutch 60 is elevatably installed at the pulsator 40 and adapted to rotate together with the pulsator 40. The float clutch 60 selectively transmits rotary power to the spin basket 30 by being elevated and lowered by buoyancy.

As shown in FIGS. 2 and 3, the center of the float clutch 60 is provided with a guide hole 62, and the shaft installation portion 41 described above is installed inside the guide hole 62. Accordingly, the elevation of the float clutch 60 is guided by the shaft installation portion 41.

In addition, to allow the float clutch 60 to be elevatably installed at the pulsator 40 and rotate together with the pulsator 40, a plurality of guide protrusions 61 allowing the float clutch 60 to be elevatably installed at the lower portion of the pulsator 40 is provided on the upper surface of the float clutch 60, and a plurality of guide grooves 43 is provided on the lower surface of the pulsator 40 such that the guide protrusions 61 are elevatably installed in the respective guide grooves 43.

The guide protrusions 61 are formed on the upper surface of the float clutch 60 such that the guide protrusions 61 extend from the center of the float clutch 60 in the radial direction of the float clutch 60 and are arranged spaced apart from each other in the circumferential direction of the float clutch 60. The guide grooves 43 are formed on the lower surface of the pulsator 40 in correspondence with the guide protrusions 61 such that the guide grooves 43 extend from the center of the pulsator 40 in the radial direction of the pulsator 40 and are arranged spaced apart from each other in the circumferential direction of the pulsator 40.

In the illustrated embodiment, the guide grooves 43 are formed at the lower side of the blades 42 in a concave shape corresponding to the shape of the blades 42 so as to efficiently use the space at the lower side of the pulsator 40. The guide protrusions 61 protrude in a shape corresponding to that of the guide grooves 43.

Also, for the float clutch 60 to stably receive rotary power from the pulsator 40 and rotate, the outer circumferential surface of the shaft installation portion 41 of the pulsator 40 is provided with a first uneven part 41 a having concave portions and convex portions alternately arranged in the circumferential direction thereof, and the inner circumferential surface of the guide hole 62 of the float clutch 60 is provided with a second uneven part 62 a having convex portions and concave portions alternately arranged in the circumferential direction thereof to match the concave portions and convex portions of the first uneven part 41 a respectively and to be elevatably installed at the first uneven part 41 a.

Also, for rotary power to be selectively transmitted to the spin basket 30 depending on the position of the float clutch 60, the spin basket 30 is provided with a coupling protrusions 33 d which is selectively coupled to the float clutch 60 depending on the position of the float clutch 60, a coupling grooves 63 to be selectively coupled to the coupling protrusions 33 d depending on the position of the float clutch 60 is provided in a concave form at the lower surface of the float clutch 60. In the illustrated embodiment, the coupling protrusions 33 d is adapted to be coupled to the coupling grooves 63 when the float clutch 60 is lowered and separated from the coupling grooves 63 when the float clutch 60 is elevated.

The coupling protrusions 33 d are formed at the hub 33 b of the drive flange 33 described above, and arranged spaced apart from each other in a circumferential direction. The coupling grooves 63 are formed on the lower surface of the float clutch 60 to correspond to the coupling protrusions 33 d, and arranged spaced apart from each other in a circumferential direction. In the illustrated embodiment, the coupling protrusions 33 d are integrated with the drive flange 33 through a process such as injection molding. Integration of the coupling protrusions 33 d with the drive flange 33 eliminates the need to use an additional component and may ensure stable reception of rotary power from float clutch 60.

Hereinafter, operation of a float clutch applied to the washing machine according to the embodiment of the present disclosure will be described with reference to the accompanying drawings.

When water fills the tub 20 to above a certain water level as in the case of washing the laundry, the float clutch 60 moves up and remains elevated due to buoyancy, as shown in FIG. 4. At this time, the coupling protrusions 33 d formed at the spin basket 30 remain separated from the coupling grooves 63 provided in the float clutch 60.

When electricity is applied to the drive unit 50 with the coupling protrusions 33 d separated from the coupling grooves 63 as above, the drive unit 50 generates rotary power and the generated rotary power is transmitted to the pulsator 40 via the rotating shaft 53 and the transmission shaft 54 to rotate the pulsator 40. The float clutch 60 receives rotary power from the pulsator 40 via the guide protrusions 61 and second uneven part 62 a and rotates together with the pulsator 40. However, the rotary power is not transmitted to the spin basket 30 as the coupling protrusions 33 d are separated from the coupling grooves 63 as described above. That is, the pulsator 40 rotates while the spin basket 30 remains at rest.

Next, when water in the tub 20 is discharged and the water level in the tub 20 is lowered below a certain level as in the case of spin-drying, buoyancy does not act on the float clutch 60. Therefore, the float clutch 60 remains lowered as shown in FIG. 5. In this condition, the coupling protrusions 33 d formed at the spin basket 30 is coupled to the coupling grooves 63 of the float clutch 60 that has been lowered.

As such, the pulsator 40 rotates with rotary power transmitted thereto via the rotating shaft 53 and the transmission shaft 54 when electricity is applied to the drive unit 50 and thus the drive unit 50 generates rotary power with the coupling protrusions 33 d coupled to the coupling grooves 63. The float clutch 60 rotates with rotary power received from the pulsator 40 via the guide protrusions 61 and second uneven part 62 a. As the float clutch 60 rotates, the spin basket 30 rotates with the rotary power received from the float clutch 60 via the coupling protrusions 33 d. That is, the pulsator 40 and the spin basket 30 rotate together.

In the illustrated embodiment, the float clutch 60 is elevatably installed at the pulsator 40 through the guide protrusions 61 and guide grooves 43 and the first uneven part 41 a and second uneven part 62 a. However, embodiments of the present disclosure are not limited thereto. The float clutch 60 may be elevatably installed at the pulsator 40 through the guide protrusions 61 and guide grooves 43, without constituents corresponding to the first uneven part 41 a and second uneven part 62 a.

Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents. 

What is claimed is:
 1. A washing machine comprising: a housing forming an external appearance of the washing machine; a tub disposed inside the housing to retain wash water; a spin basket rotatably installed in the tub; a pulsator rotatably installed in the spin basket; a drive unit to generate rotary power and transmit the rotary power to the pulsator; and a float clutch elevatably installed at the pulsator to selectively transmit the rotary power to the spin basket when elevated by buoyancy, wherein the float clutch includes at least one guide protrusion provided at an upper surface thereof to allow the float clutch to be elevatably installed at a lower portion of the pulsator, and the pulsator includes at least one guide groove provided at a lower surface thereof, the guide protrusion being elevatably installed in the guide groove.
 2. The washing machine according to claim 1, wherein the at least one guide protrusion includes a plurality of guide protrusions extending in radial direction of the float clutch and arranged spaced apart from each other in a circumferential direction of the float clutch, and the at least one guide groove includes a plurality of guide grooves extending from the pulsator outward in a radial direction of the pulsator and arranged spaced apart from each other in a circumferential direction of the pulsator.
 3. The washing machine according to claim 2, wherein the pulsator is provided, on an upper surface thereof, with a plurality of blades extending outward in a radial direction and arranged spaced apart from each other in a circumferential direction, the guide grooves are formed at a lower side of the blades in a shape corresponding to a shape of the blades, and the guide protrusions are formed in a shape corresponding to the shape of the guide grooves.
 4. The washing machine according to claim 1, wherein the drive unit includes a transmission shaft having an upper end coupled to the pulsator to transmit the rotary power to the pulsator, the pulsator includes a shaft installation portion extending from a center of a lower surface of the pulsator downward, the transmission shaft being installed at the shaft installation portion, and the float clutch includes a guide hole provided at a center thereof to allow the float clutch to be elevatably installed at the shaft installation portion.
 5. The washing machine according to claim 4, wherein the shaft installation portion includes a first uneven part provided on an outer circumferential surface thereof and provided with concave portions and convex portions alternately arranged in a circumferential direction of the shaft installation portion, and the guide hole includes a second uneven part provided on an inner circumferential surface thereof and provided with concave portions and convex portions alternately arranged in a circumferential direction of the guide hole such that the concave portions and convex portions of the second uneven part respectively match the convex portions and concave portions of the first uneven part.
 6. The washing machine according to claim 4, wherein the spin basket includes at least one coupling protrusion adapted to be selectively coupled to the float clutch depending on a position of the float clutch, and the float clutch includes at least one coupling groove formed on a lower surface thereof at a position corresponding to a position of the coupling protrusion and adapted to be selectively coupled to the coupling protrusion depending on the position of the float clutch.
 7. The washing machine according to claim 6, wherein, the at least one coupling protrusion includes a plurality of coupling protrusions arranged spaced apart from each other in a circumferential direction, and the at least one coupling groove includes a plurality of coupling grooves arranged spaced apart from each other in a circumferential direction.
 8. The washing machine according to claim 7, wherein the spin basket includes a drive flange fixed to a lower end thereof to receive the rotary power from the float clutch, the drive flange includes a hub provided with a through hole allowing the transmission shaft to be installed therethrough, and a plurality of flange portions extending from the hub outward in a radial direction and arranged spaced apart from each other in a circumferential direction, and the coupling protrusions are arranged at the hub in a circumferential direction.
 9. A washing machine comprising: a housing forming an external appearance of the washing machine; a tub disposed inside the housing to retain wash water; a spin basket rotatably installed in the tub; a pulsator rotatably installed in the spin basket; a drive unit to generate rotary power and transmit the rotary power to the pulsator; and a float clutch elevatably installed at the pulsator to selectively transmit the rotary power to the spin basket when elevated by buoyancy, wherein the spin basket includes a drive flange installed at a lower end thereof to receive power from the float clutch, the drive flange includes at least one coupling protrusion integrally protruding upward from the drive flange to be coupled to the float clutch when the float clutch is lowered, and the float clutch includes at least one coupling groove provided on a lower surface thereof to be coupled to the coupling protrusion.
 10. The washing machine according to claim 9, wherein the at least one coupling protrusion includes a plurality of coupling protrusions arranged at the drive flange spaced apart from each other in a circumferential direction, and the at least one coupling groove includes a plurality of coupling grooves arranged at the float clutch spaced apart from each other in a circumferential direction.
 11. The washing machine according to claim 10, wherein the drive flange includes a hub having the coupling protrusions, and a flange extending from the hub outward in a radial direction to be fixed to a lower surface of the spin basket.
 12. The washing machine according to claim 9, wherein the float clutch is provided therein with an empty space filled with air, thereby achieving buoyancy through the empty space.
 13. The washing machine according to claim 9, wherein the float clutch is constructed of injection molded thermoplastic or thermosetting polymer.
 14. The washing machine according to claim 9, wherein the float clutch is constructed of a material buoyant in water. 